Moulding and sealing machines

ABSTRACT

A MACHINE FOR MOLDING, FILLING AND SEALING CONTAINERS IN ONE OPERATION FROM A TUBE OF THERMOPLASTIC MATERIAL AND HAVING RELATIVELY MOVABLE MOLD PARTS.

July 20, 1.71

s. HANSEN HOULDING AND SEALING MACHINES Original Filed Oct. '19. 1964 2m MW F md 1 z mu? 1? v M u m v 6 L v Y B ..l .I. 5 l 2 /..0I Mr I W 2 MI 7 7 2 m United States Patent Int. Cl. B29d 23/03 US. (:1. 18-5BF 17Claims Matter enclosed in heavy brackets appears in the original patentbut forms no part 0 f this reissue specification; matter printed initalics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A machine for molding, filling and sealingcontainers in one operation from a tube of thermoplastic material andhaving relatively movable mold parts.

This invention relates to machines for moulding, filling and sealing acontainer made of thermoplastic material in one operation. The machinehas an extrusion head which extrudes thermoplastic tubing a section ofwhich, whilst still hot and plastic, is enclosed in a sectional mouldand a fluid under pressure is supplied to within the length of tubing inthe mould to expand the tube into contact with the mould surface andform a container. The fluid under pressure may be the material withwhich the container is to be filled or it may be, for example, a gaswhich is subsequently displaced from within the container when thematerial with which the container is to be filled is supplied in thiscase to the blown container.

A machine has previously been proposed in which the mould remains belowthe extrusion head and the fluid under pressure is supplied to thecontainer either through the extrusion head or through special ducts inthe upper part of the mould. In the first case difficulty arises inproviding holding jaws for supporting the length of tubing during thefilling operation and special mould sections for sealing the top of thefilled container. In the second case fluid supply nozzles are passedthrough the mould section and protrude into the mould in order to piercethrough the length of tubing. With this arrangement there is littlespace available to accommodate the supply nozzles, which may be hollowneedles and which become easily blocked as they pierce through thelength of plastic tubing in the mould.

In accordance with the present invention a machine for moulding, fillingand sealing containers in one operation comprises an extrusion head forextruding thermoplastic tubing, at least one sectional mould assemblywhich is arranged to enclose a length of the extruded tubing and thesections of which are each formed with lower and upper parts defininglower and upper moulds for shaping the body and for shaping and sealingthe top of the container respectively, and a filling nozzle which isarranged to be introduced into the open upper end of the length oftubing within the mould assembly for supplying fluid under pressure toexpand the tubing into contact with the lower mould and form the body ofthe container, the lower part of each section carrying above the upperpart of the same section a suction device for applying suction to theoutside of the upper end of the length of tubing within the mouldassembly to support the tubing during shaping of the container body butwith the tubing out of contact with the upper mould, and the upper partof each section being provided with a further suction device forapplying suction to the outside of the tubing for assisting in shapingRe. 27,155 Reissuecl July 20, 1971 and sealing the top of the containerafter the container has been filled through the filling nozzle.

Preferably, the mould assembly is mounted on a slide block whichreciprocates between the extrusion head and the filling nozzle, themould assembly being in two sections, the lower parts of which areslidable relatively to the block and the upper parts of which areslidably relatively to the lower parts both perpendicularly to thedirection of reciprocation of the slide block. The sliding movement ofthe slide block and other operations of the machine may be controlled bymeans of limit switches.

In order to keep the top part of the length of tubing enclosed in themould as warm and plastic as possible so that the top of the containercan be successfully shaped and sealed after the container has beenfilled either one or both of the outer surfaces of the filling nozzleand the upper portions of the lower parts of the mould sections may bethermally insulated. For example, the lower parts of each mould sectionmay be lined with a thermally insulating material at their upper ends,and the tip of the filling nozzle which extends down within the lengthof tubing into the top of the lower mould is covered with a layer ofthermally insulated material, the arrangement being such that when themandrel is introduced into the mould assembly for expanding the body ofthe container, part of the length of the tubing is gripped between thecovering on the tip of the nozzle and the lining of the lower mould.Preferably the part of the length of tubing is gripped between a conicaltip on the nozzle and a complementary conical seating at the top of thelower mould when the body of the container is blown.

One example of a machine constructed in accordance with the invention isillustrated in the accompanying drawings, in which:

FIGURE 1 is a longitudinal section taken on the line II in FIGURE 2 inthe direction of the arrows; and

FIGURE 2 is a section taken on the line IIII in FIG- URE 1 in thedirection of the arrows but to a diti'erent scale.

On a table 1 a slide block 2 can be moved by means of a hydraulically orpneumatically operated piston-cylinder unit 3 from a position below anextrusion head 4 of an extruder 5 to a position below a hollow fillingnozzle 6 which is secured to the table 1 and which can be raised or loW-ered. The extruder 5 produces a continuous length of thermoplastictubing 7, such as polythene or polyvinylchloride and is fitted with acutter 8 for cutting ofi lengths of the plastic tubing 7. The nozzle 6is connected to a duct 9, which is in turn connected to a source of airpressure and to a filling line 10 for the supply of the material withwhich the container is to be filled.

The slide block 2 carries the lower parts 12 and 12 of two mould halveswhich are capable of sliding at right angles to the sliding direction ofthe piston of the piston/ cylinder unit 3. Fitted to each lower mouldpart 12, 12' by means of a connecting piece 13, 13 is a vacuum chamber14, 14'. The side of the vacuum chamber adjacent to the length of tubingis provided with suction nozzles 15, 15. An upper mould part 16 capableof sliding on the lower mould half 12 and for producing the top of thecontainer together with upper part 16' of the other mould half islocated between the vacuum chamber 14 and the lower mould part 12. Thelower mould part 12 is movable on the slide block 2 by means of apiston/cylinder unit 17, and the upper mould part 16 is movable on thelower mould part 12 by means of a piston/cylinder unit 18. The top innersurface of the bottom mould part 12 and the exterior of the nozzle areprovided with a heatinsulating covering 19, 1'9 and 19". The upper moulddefined by the parts 16, 16' is, similarly to the vacuum chamber 14,connected to a suction source- (not illusrated), by way of a duct 24 andis provided with suction lozzles 20.

The right-hand mould half shown in FIGURE 2 is dentical to and markedwith the same reference numerals [S the left-hand half, except that tothe numerals for he former are primed.

FIGURES 1 and 2 show the mould assembly posiioned below the head 4 ofthe extruder 5. The extruder aroduces a piece of tubing 7, the leadingend of which :an just be seen. As soon as the tubing 7 has reachedsuficient length, the two lower mould parts 12, 12. move to- ;ether andenclose a length of the tubing 7 between them vithin a lower mould. Anyof the tubing protruding at he bottom is sheared off by the mould anddrops down hrough an opening 21. When the lower mould part 12 moves, theupper mould part 16 is moved with it, however, vith the [upper] lowermould closing completely. The ube piece is held at its upper end by thevacuum in the 'acuum chamber 14, 14', before it is cut off at a certainength by the cutter 8.

The partially closed mould assembly with the lower nould fully closedthen moves under the filling nozzle 6 vhich is lowered coaxially intothe length of tubing 7 vithin the mould until the nozzle rests on thelower mould arts 12, 12' with the length of tubing 7 interposed beweenthe nozzle and the lower mould. For this purpose he lining 19, 19' has aconically shaped extension on its lpper side and the end of the mandrelwhich is provided vith a heat-insulating lining 19" is of complementaryhape. Compressed air is first injected through the duct and nozzle 6into the tubing 7 within the mould and he air cannot escape unless acertain pressure is over ome, so that at this stage the still plastictubing 7 is ex anded against the lower mould 12, 12' and forms the |odyof the container. Subsequently the filling material liquid, paste,pulverised or grannular materials etc.) is ed into the body of thealready formed container through he duct 10 and nozzle 6 and thecompressed air is dis- IIaced from the container. When the container isfilled the lOZZlE 6 is lifted and the upper mold 16, 16' then closesompletely to form and seal the container neck. In order to nsure thatthe head part of the container is well formed, he corresponding area ofthe tubing which is, at this tage, still plastic is held against theupper mould parts 16, 6' by suction. The top end of the tube is still ina plastic ondition as the conduction of heat to the lower mould 2, 12 isconsiderably decreased by the lining 1 9, 1'9", .9. Following .closingof the container on completion of he neck the vacuum source is switchedoil? and the halves f the lower mould 12, 12' and the upper mould 16,16' pen and then revert to their datum position. When the noulds openthe filled container falls through holes 22 nd 23 in the slide block 2and table 1. The mould 12, 2716, 16' again moves under the extrusionhead 4 of the xtruder to enclose the next length of plastic tubing 7 ndthe operation to produce a filled and closed container egins afresh.

The movement of the upper and lower mould parts 12, 2 and 16, 16', thedischarge of the tube 7 from the head i of the extruder 5, the injectionof compressed air and lling of the material as well as the necessarylifting and Jwering operations of the nozzle 6 are controlled by leansof limit stops, time delay relays and similar switch quipment so thatthe process for the production of a conliner and subsequent containersis automatic.

The machine can also be used without supplying comressed air through theduct 9. In this case the tube is xpanded so that it takes up the shapeof the mould by me introduction under pressure of fluid with which theontainer is to be filled. Air trapped in the tube may scape both throughthe filling nozzle 6 when sufficient ressure has built up.

I claim:

1. A machine for moulding, filling and sealing conainers in oneoperation and comprising an extrusion head adapted to extrude a lengthof thermoplastic tubing, at least one sectional mould assembly which isarranged to enclose said length of extruded tubing and. a filling nozzlespaced from the extrusion head adapted to be introduced into the openend of said length of tubing within said mould assembly and to supply.fluid under pressure to expand said length of tubing into contact with apart of said mould and form a body of said container, the sectionalmould assembly being movable between the extrusion head and the fillingnozzle and which comprises lower parts of said mould sections adapted toshape the body of said container, upper parts of said mould sectionsadapted to shape and seal the top of said container, first suctionnozzles, means applying suction to said first suction nozzles, meansmounting said first suction nozzles on said lower parts at a level abovesaid upper parts of said mould sections whereby said first suctionnozzles are adapted to apply suction to the outside of the upper end ofsaid length of tubing Within said mould assembly to support said tubingduring the shaping of said body of said container with said tubingout'of contact with said upper parts of said mould sections, secondsuction nozzles carried by said upper parts of said mould sections, andmeans applying suction to said second suction nozzles for assisting inshaping and sealing the top of said container after said container hasbeen filled through said filling nozzle.

2. A machine according to claim 1, wherein said mould assembly is formedin two sections and said machine further comprises a slide blockmounting said mould assembly, means slidably mounting said block forreciprocatory motion between said extrusion head and said fillingnozzle, means slidably mounting said lower parts of said mould sectionstowards and away from one another on said slide block in a directionperpendicular to the dime tion of reciprocation of said slide block, andmeans slidably mounting said upper parts of the said mould sectionrelatively to the said lower parts also toward and away .from oneanother in a direction perpendicular to said reciprocation of said slideblock.

3. A machine according to claim 1, further comprising a tip on saidfilling nozzle, upper portions of said lower part of said mould sectionsadapted to receive said tip during expansion of said length of tubing toform said body of said container, and thermally insulating means carriedby at least one of said co-operating tip and upper portions.

4. A machine according to claim 1, further comprising a tip on saidfilling nozzle, upper portions of said lower part of said mould sectionsadapted to receive said tip during expansion of said length of tubing toform said body of said container, and thermally insulating means carriedby at least one of said co-operating tip and upper portions, saidthermally insulating means comprising a lining to said upper portionsand a covering to said tip whereby a part of said length of tubing isgripped between said lining and said covering during its formation ofsaid body of said container.

5. A machine according to claim 3, wherein said covering on said tip isconical and said lining forms a complementary conical seating for saidtip.

6. A machine for producing, filling and sealing containers from a tubeof thermo-plastic material comprising a pair of relatively movable moldforms for forming a main body portion of the container including thebottom part of the container, a pair of slidable upper mold forms toform the head of the container, divided holding members for the tubingwhereby the upper mold forms when the relatively movable mold forms areclosed will maintain and form the head of the container, said holdingmembers each having a chamber therein, with suction nozzles therein tohold the tube and said upper mold forms each having a chamber withsuction nozzles for the head to form closing parts which during fillingare spaced form the tubing and after filling are closed.

7. A machine for manufacturing a closed container filled with a flowablematerial comprising a mold, means for extruding a length of heatedthermoplastic material in the shape of a hollow tubular body into saidmold, means for establishing a predetermined length of thermoplasticmaterial in the form of a tubular body, means for closing said mold, thebottom of said tubular body being closed by said mold, means forapplying a vacuum to support and hold the upper end of said tubularbody, and a nozzle adapted to be introduced into the open end of saidhollow tubular body, means for applying a difierential pressure throughsaid nozzle to the interior of said heated tubular body to cause it tobe expanded to conform to the shape of said mold thereby forming acontainer body and means for filling said container body through saidnozzle with a flowable material, a tip on said nozzle, said mold beingformed to accommodate said tip, thermally insulating means carried by atleast one of said tip and the portion of said mold formed to accommodatesaid tip to minimize heat transfer from the adjacent plastic, means forclosing the expanded and filled container body after removal of saidnozzle, and means for removing said closed container from said mold.

8. The machine of claim 7, wherein said insulating means is applied tosaid tip.

9. A machine for manufacturing a closed container filled with a flowablematerial comprising a mold, means for extruding a length of heatedthermoplastic material in the shape of a hollow tubular body into saidmold, means for establishing a predetermined length of thermoplasticmaterial in the form of a tubular body, means for closing said mold, thebottom of said tubular body being closed by said mold, means forapplying a vacuum to support and hold the upper end of said tubularbody, and a nozzle adapted to be introduced into the open end of said.hollow tubular body, means for applying a differential pressure throughsaid nozzle to the interior of said heated thermoplastic tubing to causeit to be expanded to conform to the shape of said mold thereby forming acontainer body and means for filling said container body through saidnozzle with a flowable material, a tip on said nozzle, said mold beingformed to accommodate said tip,

means for closing the expanded and filled container body after removalof said nozzle, said closing means comprising vacuum jaws which form andshape a cap on said container body to close and seal it, and means forremoving said closed container from said mold.

10. The machine of claim 9, further including thermally insulating meanscarried by at least one of said tip and the portion of said mold formedto accommodate said tip to minimize heat transfer from the adjacentplastic.

11. A machine for manufacturing a closed container filled with aflowable material comprising a mold, means for extruding a length ofheated thermoplastic material in the shape of a hollow tubular body intosaid mold, means for establishing a predetermined length ofthermoplastic material in the form of a tubular body, means for closingsaid mold, the bottom of said tubular body being closed by said mold,and a nozzle adapted to be introduced into the open end of said hollowtubular body, means for applying a differential pressure through saidnozzle to the interior of said heated tubular body to cause it to beexpanded to conform to the shape of said mold thereby forming acontainer body and means for filling said container body through saidnozzle with a flowable material, a tip on said nozzle, said mold beingformed to accommodate said tip, thermally insulating means carried by atleast one of said tip and the portion of said mold formed to accommodatesaid tip to minimize heat transfer from the adjacent plastic, means forapplying pressure differential means to support and hold the upper endof said tubular body, means for closing the expanded and filledcontainer body after removal of said nozzle, and means for removing saidclosed container from said mold.

12. The machine of claim 11, wherein said insulating means is applied tosaid tip.

13. The machine of claim 11, wherein said means for applying pressuredifierential means to support the upper end of said tubular body is avacuum.

14. A machine for manufacturing a closed container filled with aflowable material comprising a mold, means for extruding a length ofheated thermoplastic material in the shape of a hollow tubular body intosaid mold, means for establishing a predetermined length ofthermoplastic material in the form of a tubular body, means for closingsaid mold, the bottom of said tubular body being closed by said mold,and a nozzle adapted to be introduced into the open end of said hollowtubular body, means for applying a difierential pressure through saidnozzle to the interior of said heated thermoplastic tubing to cause itto be expanded to conform to the shape of said mold thereby forming acontainer body and means for filling said container body through saidnozzle with a flowable material, a tip on said nozzle, said mold beingformed to accommodate said tip, means for applying pressure difierentialmeans to support and hold the upper end of said tubular body, means forclosing the expanded and filled container body after removal of saidnozzle, said closing means comprising vacuum jaws which form and shape acap on said container body to close and seal it, and means for removingsaid closed container from said mold.

15. The machine of claim 14, further including thermally insulatingmeans carried by at least one of said tip and the portion of said moldformed to accommodate said tip to minimize heat transfer from theadjacent plastic.

16. The machine of claim 14, wherein said means for applying pressuredifferential means to support the upper end of said tubular body is avacuum.

17. The machine of claim 15, wherein said means for applying pressurediflerential means to support the upper end of said tubular body is avacuum.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this parent or the original patent.

UNITED STATES PATENTS 2,959,812 11/1960 Allen 18-5 3,048,889 8/1962Fischer et a1. 18-5 3,251,915 5/1966 Pechthold 53-140X 3,358,062 12/1967Lemelson 53-140X 3,423,495 1/1969 Bachner 185X 2,503,171 4/1950 Power53140X 2,978,745 4/1961 Langecker 185X 3,016,669 1/1962 Grosclaude 185XFOREIGN PATENTS 704,758 3/1965 Canada 18-5BF J. SPENCER OVERHOLSER,Primary Examiner M. O. SUTTON, Assistant Examiner

